The present invention relates to a linear motor for generating linear movement. More particularly, the present invention relates to a linear motor armature having a number of coils aligned in the direction of the linear movement.
A linear motor for a machine tool is known that causes a moving element, such as a table and a head, to linearly move at high speed. As a moving element of a machine tool is large in weight, and there is no speed reducing mechanism between the linear motor and the moving element, such linear motor needs to generate a large thrust. A linear motor for a machine tool typically includes a row of permanent magnets that are attached to a magnetic plate, and includes coils wound around cores at the top surfaces that face an air gap. Typically, a linear motor having a larger thrust is larger in size than a linear motor having a smaller thrust, and generates more heat in the coils than a smaller thrust linear motor does. For a larger thrust linear motor, more heat results as a result of including a cooling device for the coils, which enlarges the size of the linear motor.
Thanks to newer, more effective cooling devices, and stronger permanent magnets, compact linear motors having a sufficient thrust can be supplied for machine tools. Also, an effort has been directed towards making a moving element of a machine tool as light in weight as possible to avoid requiring an excessively large thrust to move the element. Recently, linear motors have become more widely used in a variety of machine tools. Accordingly, there is a need for linear motors having different thrusts.
An object of the present invention is to provide a linear motor armature that can be easily and promptly manufactured according to the required thrust and size needed to move a moving element of a machine tool. Another object of the present invention is to provide a method of manufacturing a linear motor armature with an excellent cooling capability that can be provided to linear motor armatures of varying sizes.
In order to achieve the above objects, a linear motor armature is constructed by connecting in series: a front module, at least one intermediate module following the front module, and a back module following the at least one intermediate module. The front module includes a first fluid passage, one end of which can be connected to the outside of the armature, and the other end of which is open to the back edge of the front module; and a fifth fluid passage one end of which can be connected to the outside of the armature, and the other end of which is open at the back edge of the front module. The at least one intermediate module includes a second fluid passage, one end of which is open at the front edge of the intermediate module, and the other end of which is open at the back edge of the intermediate module; and a fourth fluid passage, one end of which is open at the front edge of the intermediate module, and the other end of which is open at the back edge of the intermediate module. The intermediate module further includes a coil and a flat cooling tube having a U-shaped fold into which the coil, for example, fits into. The back module includes a third fluid passage, both ends of which are open at the front edge of the back module. Coolant can be circulated in the first fluid passage, the second fluid passage, the third fluid passage, the fourth fluid passage, and the fifth fluid passage, respectively.
Additional objects, advantages and novel features of the invention will be set forth in the description that follows, and will become apparent to those skilled in the art upon reading this description or practicing the invention. The objects and advantages of the invention may be realized and attained by practicing the invention as recited in the appended claims.